As is well known in the prior art, with reference to FIGS. 1 and 2, many cylinder locks include a plug 1 (also called a tumbler) arranged for rotation in a body 2 wherein the plug 1 and the body 2 are provided with a number of bores 3 and 4, respectively, in which plug pins and driver pins are disposed. The plug 1 is formed with a keyway for inserting therein a key 5. The driver pins are aligned with the plug pins, and the plug and driver pins have varying lengths that define a key cut combination. Upon insertion of a key with the correct key cut combination, the faces of the plug pins and driver pins that touch each other are aligned flush with the circumferential surface of the plug 1, referred to as the shear line, and the plug 1 may be rotated to actuate the lock. If the key cut combination is not correct, at least one of the driver and plug pins will cross over the shear line and prevent rotation of the plug 1, and thus prevent actuation of the lock.
FIGS. 1 and 2 show a European profile double cylinder lock. The cylinder lock actuates a common cam 6, which fits in a recess 7 formed in the body. The plug 1 may be formed with a longitudinal groove 8 for the key. Different holes 9 may be formed in the plug 1 and the body 2 for placing therein hardened, anti-drilling pins (not shown).
It is common to construct the plug 1 and body 2 from relatively soft metals, such as brass, although other metals are also used, such as different steel alloys. The plug and body are generally made by various machining manufacturing steps. It would be desirable to reduce manufacturing costs for making the cylinder lock.
The key is commonly made from metal, such as nickel silver or brass, but other metals are also used. The key is generally made in a coining or stamping process, whereas keyway profiles, key cuts and other features on the key are generally made by machining. Some cylinder locks come in different lengths, and the cylinder locksmith or installer has to select the proper cylinder length to match the dimensions of the door thickness. In addition, the inner side of the door often has a turning knob, that is, it is not operated by a key. These considerations increase inventory costs for different lengths of cylinder locks, and increase the difficulty of installation for the cylinder locksmith; sometimes the cylinder locksmith has to come twice to the customer—once to get the proper dimensions for installation and another time to actually install the cylinder lock.